UpdateOperations.add() to an array field that doesn't exist yet

[tony_k]

newbie morphia user having what is probably a stupid issue:

have a three-level object graph Widgit has a list of Whatsits has a
list of Whoosits.

so i create a Widget with an empty list of Whatsits to start with.

then i attempt:

---
// repo is a BasicDAO<Widgit, ObjectId>...
//
UpdateOperations<Widgit> ops =
repo.createUpdateOperations().add("whatsits.whoosits", new Whoosit());
---

i get: MongoException: can't append to array using string field name
[whoosits]

i was hoping morphia/mongo would create the "whoosits" field as an
array since it didn't exist, but no dice.

any guidance appreciated...!

[Scott Hernandez]

Can you provide example classes or an example document (json) with
what you are trying to do? It is hard to update things deep in nested
arrays of arrays.

[tony_k]

@Entity
public class Widgit
{
@Id
private ObjectId id;

private List<Whatsit> whatsits = new ArrayList<Whatsit>();

public ObjectId getId()
{
return id;
}

public List<Whatsit> getWhatsits()
{
return whatsits;
}

public void setWhatsits(List<Whatsit> whatsits)
{
this.whatsits = whatsits;

[tony_k]

oops, sorry about the earlier mis-post:

@Entity
public class Widgit
{
@Id
private ObjectId id;

private List<Whatsit> whatsits = new ArrayList<Whatsit>();

public ObjectId getId()
{
return id;
}

public List<Whatsit> getWhatsits()
{
return whatsits;
}

public void setWhatsits(List<Whatsit> whatsits)
{
this.whatsits = whatsits;
}
}

public class Whatsit
{
private Integer id;

private List<Whoosit> whoosits = new ArrayList<Whoosit>();

protected Whatsit()
{
}

public Whatsit(Integer id)
{
this.id = id;
}

public Integer getId()
{
return id;
}

public List<Whoosit> getWhoosits()
{
return whoosits;
}

public void setWhoosits(List<Whoosit> whoosits)
{
this.whoosits = whoosits;
}
}


public class Whoosit
{
private Integer id;

protected Whoosit()
{
}

public Whoosit(Integer id)
{
this.id = id;
}

public Integer getId()
{
return id;
}
}

//... repo is a BasicDAO...
//
Widgit widgit = new Widgit();
widgit.getWhatsits().add(new Whatsit(0));
repo.save(widgit);
Query<Widgit> q =
repo.createQuery().field(Mapper.ID_KEY).equal(widgit.getId()).field("whatsits.id").equal(0);
Whoosit whoosit = new Whoosit(1);
UpdateOperations<Widgit> ops =
repo.createUpdateOperations().add("whatsits.whoosits", whoosit);
UpdateResults<Widgit> results = repo.update(q, ops);
//...

> db.Widgit.find()
{ "_id" : ObjectId("4e14faddc0f7a9dfecd662d0"), "className" :
"com.kerz.morphia.Widgit", "whatsits" : [ { "id" : 0 } ] }

On Jul 6, 4:03 pm, Scott Hernandez <scotthernan...@gmail.com> wrote:

[tony_k]

and the trace if it's helpful:

com.mongodb.MongoException: can't append to array using string field
name [whoosits]
at com.mongodb.CommandResult.getException(CommandResult.java:82)
at com.mongodb.CommandResult.throwOnError(CommandResult.java:116)
at com.mongodb.DBTCPConnector._checkWriteError(DBTCPConnector.java:
125)
at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:147)
at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:131)
at com.mongodb.DBApiLayer$MyCollection.update(DBApiLayer.java:335)
at com.google.code.morphia.DatastoreImpl.update(DatastoreImpl.java:
950)
at com.google.code.morphia.DatastoreImpl.update(DatastoreImpl.java:
916)
at com.google.code.morphia.DatastoreImpl.update(DatastoreImpl.java:
921)
at com.google.code.morphia.DatastoreImpl.update(DatastoreImpl.java:
837)
at com.google.code.morphia.dao.BasicDAO.update(BasicDAO.java:129)
at com.kerz.morphia.MorphiaTest.basic(MorphiaTest.java:49)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod
$1.runReflectiveCall(FrameworkMethod.java:44)
at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:
15)
at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:
41)
at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:
20)
at
org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:
74)
at
org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:
82)
at
org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:
72)
at
org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:
240)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:
49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at
org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:
61)
at
org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:
70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at
org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:
180)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:
49)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:
38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:
467)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:
683)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:
390)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:
197)

> repo.createQuery().field(Mapper.ID_KEY).equal(widgit.getId()).field("whatsi ts.id").equal(0);